Recently, studies on medical materials utilizing various polymer materials have been in progress, and their application to membranes for artificial kidney, membranes for blood plasma separation, catheters, stents, membranes for artificial lung, artificial blood vessels, anti-adhesion barriers, artificial skin, and the like, is possible. For such applications, synthetic polymer materials, which are foreign matters in the living body, are used in contact with biological tissue, or body fluid such as blood. Accordingly, it can be desirable for the medical materials to have biocompatibility. The desired biocompatibility of the medical materials varies depending on their purpose or usage, but it can be desirable for medical materials used as materials in contact with blood to have antithrombotic properties such as, for example, inhibition of the blood coagulation system, suppression of adhesion and activation of platelets, and inhibition of activation of the complement system.
In general, impartment of the antithrombotic property to a medical equipment is carried out by a method of coating a substrate constituting the medical equipment with an antithrombotic material (antithrombotic coating material), or a method of fixing an antithrombotic material to the surface of the substrate.
For example, JP-A-4-152952 discloses a membrane for artificial organs and a medical equipment for use in contact with biological tissue or blood, which have, on their surfaces, a synthetic polymer that satisfies effects of suppression of adhesion and activation of platelets, and inhibition of activation of the complement system, as well as biocompatibility which is affinity with the biological tissue. In JP-A-4-152952, polymethoxyethyl acrylate (PMEA) or the like is disclosed as a synthetic polymer that is an antithrombotic material.